Drum unloader

ABSTRACT

A bucket-and-bail container which is designed to be placed over an open topped drum of solid particulate materials, such as grinding balls, and, by manipulation of the bail, inverted so that the particulate materials are emptied into the bucket container. The bucket container can then be safely transported to a preselected unloading station and then emptied via a door in the bottom. After emptying the empty drum is again inverted and dumped out of the bucket container. A special feature of the invention is the provision of a safety interlock which prevents the doors in the bucket container from being opened until the bucket is positively located at the unloading station.

United States Patent Inventor App]. No. Filed Patented Assignee Priority DRUM UNLOADER 11 Claims, 15 Drawing Figs.

Int. Cl. 1365b 69/00 FieldoiSearch 214/314, 312, 317, 307

Primary Examiner-Gerald M. Forlenza Assistant Examiner-Lawrence J. Oresky Attorney-Stevens, Davis, Miller & Mosher ABSTRACT: A bucket-and-bail container which is designed to be placed over an open topped drum of solid particulate materials, such as grinding balls, and, by manipulation of the bail, inverted so that the particulate materials are emptied into the bucket container. The bucket container can then be safely transported to a preselected unloading station and then emptied via a door in the bottom. After emptying the empty drum is again inverted and dumped out of the bucket container. A special feature of the invention is the provision of a safety interlock which prevents the doors in the bucket container from being opened until the bucket is positively located at the unloading station.

PATENTED SEP28 mm 3508 757 sum 1 nr 6 mama] Stratum 3506.751

' sum 3 BF 6 PATENTED .8EP28 197i SHEU 8 OF 6 DRUM UNLOADER This invention relates to generally to material handling ap paratus and more particularly to a bucket and ball container for inverting open drums of solid particulate materials, transporting and dumping said materials.

In many industries, for example, in the metallurgical, mining and cement industries, heavy particular materials required in operations are delivered to the plant in open drums or containers, for ease of transportation, handling and storage. When required for use, the contents must be emptied out of the drums. Examples of the type materials delivered in this manner are ferroalloys to metallurgical plants and'grinding balls to mines, mills and cement plants. These materials are frequently of very high density so that a 45-gallon oil drum, which, among other, is commonly used for the purpose, may weigh upwards of 2,000 pounds. In the case of relatively low cost materials such as grinding balls which do not require much protection from damage, contamination or theft, it is common practice to use and reuse old drums without tops. These drums are frequently damaged and are often weakened by rust even before use in this manner. Bearing in mind the considerable weight involved, the inversion of these drums to empty the contents into, for example, a furnace, hopper or ball mill presents considerable problems. Common expedients include the use of mobile lift trucks equipped with special hydraulic caliper jaws which grip the drums around the middle to lift and then turn the drum. Unfortunately, the drums are frequently crushed by the jaws as they are comparatively weak in comparison to the force which must be applied to obtain sufiicient grip to lift the drum, particularly as they are often damaged even before they are used for the present purpose. Further problems are encountered when drums which are only partially filled are handled. Rope wire slings suspended from overhead cranes are often employed to invert drums to empty their contents, but this is time consuming, requires considerable manual labor and is a constant safety hazard due to the incidence of slipping and spillage of the heavy contents.

It is, therefore, an object of the present invention to overcome the disadvantages of the prior art and provide a relatively inexpensive bucketand-bail-type device whereby open top drums or other containers containing particulate loads may be easily and safely inverted, the load transported to a desired location and safely dumped. It is particularly desirable that the load shall not dump accidentally during transportation and it is therefore a further object to provide a novel safety interlock whereby dumping of the load is prevented until the bucket is positively located at the unloading position.

These and other objects will become more apparent after referring to the detailed specification hereinbelow and to the attached drawings which are illustrative but not limiting of the present invention and in which:

FIG. 1 is a perspective view of the unloader of the present invention in the load or inverted position.

FIG. 2 is a perspective view of the unloader of the present invention in the unload or upright position.

FIG. 3 is a closeup perspective view of the unloader, showing the locking mechanism.

FIG. 4 is a front elevational view of the flip-flop bail stop, and

FIGS. 5-44 are a series of diagrammatic sketches showing the sequence of operations involved in loading, inverting, dumping and returning drums.

FIG. shows details of the locking mechanism.

Referring firstly to FIGS. 1, 2 and 3, which illustrate a preferred embodiment, reference numeral 2 designates a conventional lifting bail, having a crossmember 3 and arms appendant at the ends thereof, adapted to receive a conventional crane hook and mounted to the sides thereof, adapted to receive a conventional crane hook and mounted to the sides of a rectangular drum unloader frame 4 by means of trunnions 6, so that the entire frame 4 and a bucket 5 encompassed by the frame may be rotated through l80with respect to the bail.

Bucket 5 is of the bottom-opening type, being provided with overlapping doors 8 and 10 having closing arms 12 and 14 respectively, and being rigidly mounted within the frame 4. Frame 4 is fabricated from any suitable material for heavy duty applications such as steel angles and comprises, when considered in the start or inverted position, four substantially vertical members, 16, 18, 20 and 22, arranged to form a rectangle, all somewhat taller than the height of the bucket 5, members 16 and 20 being rigidly interconnected by upper and lower horizontal members 24 and 26 respectively, members 18 and 22 being rigidly interconnected by upper and lower horizontal members 28 and 30 respectively. Members 16 and 18 are interconnected by lower horizontal member 32, the members 20 and 22 are interconnected by an intermediate horizontal member 34. Members 20 and 22 are positioned so that they are parallel in vertical relation, to each other, and sloping inwardly and upwardly at an angle of about 10 to 15 towards members 16 and 18 from the intermediate member 34, and sloping inwardly and downwardly at an angle of about 45 towards members 16 and 18 from the intermediate horizontal member 34. The reason for sloping the members 20 and 22 will be more apparent hereinafter. Trunnion-supporting members 36 and 38 may be provided on the frame 4, or the trunnions 6 may be mounted directly on the bucket 5, which, as herein before mentioned, is rigidly mounted between members 16, 18, 20 and 22 with the rim 7 at a level approximating that of intermediate horizontal member 34. Bucket 5 is provided with bail stops 40, 42 and similar stops (not shown) and the other side adjacent the trunnions 6 to prevent the bail moving past the vertical position towards the plane 20 and 22.

Frame 4 is also provided with a bail-lock-door-unlock means, indicated generally as 48 which will be described in more detail herein below, and with a pair of gravity flip-flop bail stops 50 and 52 mounted on members 18 and 16 respectively. As shown in FIG. 4, bail stops 50 and 52 comprise a flat plate 51 asymmetrically mounted in a vertical plane on a pivot pin 54 so that the plate is free to pivot through about in a vertical plane. Movements in excess of about 90 is prevented by cover plates 56, which act as stops. Plate 51 is provided with a pair of cars 58 and 60 which extend beyond members 16 and 18 into the plane of rotation of bail 2. As indicated plate 51 is mounted asymmetrically so that its center of rotation is located between the overbalance end 62 and the pivot pin 54, and therefore remote from cars 58 and 60. In the inverted position, therefore, over balance 62 acts, under gravity, to turn plate 51 so that car 58 is withdrawn slightly from the plane of rotation of bail 2, conversely car 60 is extended into the said plane. When bail crossmember 3 is lowered the bail arm strikes car 60, forcing it downwardly against the weight of overbalance 62 to allow passage past the ear. As soon as the arm clears the ear, overbalance 62 returns to its original rest position against stop cover plate 56, ear 60 again being extended. If the bail arm is then brought back to the lower side of ear 60 it cannot pass as the counterbalance is at stop 56. Conversely, when the unloader is in the upright position as in FIG. 2, the bail contacts and passes ear 58 when rotated in one direction and contacts and is stopped by ear 58 when rotated in the opposite direction. This aspect will be more fully described when the operation of the unloader is detailed.

The bail-lock-door-unlock means 48, will now be described in more detail. A vertical rod 63 is mounted in parallel sliding relation within member 18. In the inverted position shown in FIG. 1, the rod extends to be flush with upper horizontal member 28. In the upright position as shown in FIG. 2, rod 63 extends beyond member 28 to form an extended tip 64. Rod 63 is provided with a handle 66 which extends through member 18 so that the rod 63 may be raised or lowered as shown in FIG. 3. A horizontal spring cam bail lock member 68 rigidly mounted on rod 63 between tip 64 and handle 66 so that, when handle 66 is in its lowest position (as in FIG. 1) and tip 64 is flush with member 28, lock member 68 is positively aligned with a stop 70 on ball 2 to hold the bail locked in the vertical position. With the equipment still in the initial position, when handle 66 is raised, extending tip 64, lock member 68 is raised out of alignment with stop 70 so that bail 2 may rotate about trunnions 6. Handle 66 is also provided with a locking means 72 which acts on door closing arm 12 such that when handle 66 is in its low position, with the ball 2 locked as in FIG. 1, locking means 72 is out of engagement with arm 12 and the door 8 can be opened by rotating the arm about a pivot 9; that is arm 12 can be moved outwardly free of stop 11 when locking means 72 no longer blocks it. When handle 66 is raised as shown in FIG. 3, thus freeing the bail 2, locking means 72 moved into operative engagement with arm 12, when door 8 is closed, preventing movement thereof by holding arm 12 resiliently inwardly against a stop Ill and thus preventing accidental opening of doors 8 and 10.

Having described the novel unloader in terms of its component parts, its mode of operation will now be described with reference to FIGS. 5-14 which are diagrammatic sketches illustrating the sequence of event. A 45-gal. drum '74 containing, for example, Ni-Hard (Trademark for a nickel-iron alloy) grinding balls, and weighing approximately 2,000 pounds is to be emptied into a ball mill. The unloader, in the inverted position, is suspended from an overhead or mobile crane and lowered over the drum 74 as shown in FIG. 5. At this point handle 66 is in the lower position so that the door lock 72 is in the inoperative position and lock member 68 is aligned with stop 70 to lock the bail in the upright position.

Handle 66 is then raised thereby locking arm 12 with member 72 and also moving lock member 68 out of alignment with stop and raising tip 62 out of alignment with stop 70 and raising tip 64 as shown in FIG. 6. Bail 2 may then be lowered past ears 58 and 60 of the flip-flop stops 50 and 52, with the assured that the overlapping doors 8 and 10 cannot open accidentally. Once the bail is past car 60 the bail 2 may be raised as shown in FIG. 7 so that it contacts ear 60. As the vertical lifting of bail crossmember 3 in continued, the equipment commences to rotate about point 76, until it is resting on the 45 sloping portions of members 20 and 22, then the equipment rotates about point 78 until it is resting on the l-15 sloping portions of members 20 and 22 as shown in FIG. 8. During these rotational movements, the balls in the drum 74 shift in position and when the position of FIG. 8 is reached they start spilling out of the drum and into the bucket 5. The change in position of the center of gravity of the load greatly facilitates the turning action. It will be noted that because of the inward slope of members 20 and 22, and open top of drum 74 is lower than the bottom of the drum when the unloader reaches the position shown in FIG. 8.

A continued upward pull on the bail crossmember 3 then causes rotation about the point 80 and completes the rotation to the upright position shown in FIG. 2. The load of balls has now been completely emptied from the drum 74 into bucket in frame 4 and the balls now rest on doors 8 and 10. Note that the tip 64 still protrudes past members 28. The inverted drum can now be safely transported in the bucket 5 to the dumping station at the top of the ball mill or other predetermined point. When the unloader is positioned over the open ball mill load point 82, tip 64 comes into contact with the flat flange 84 surrounding the load point and against which the load point cover plate is bolted as shown in FIG. 9. The weight of the unloader with its load of balls forces the tip 64 upwards thereby raising handle 66, bearing in mind that the bucket is now in the upright position, and thereby causing locking means '72 to move out of engagement with arm 12. Arm 112 can be then moved outwardly clear of stop 11 and due to the weight of the balls against the doors 8 and 10 it will rotate in the direction shown by arrow in FIG. 3. A stop 84 (FIGS. 1 and 2) may be provided to prevent excessive movement of the arms. As previously indicated, doors 8 and 10 overlap and in a preferred embodiment of a short door 8 overlaps a longer door 10 so that the longer door takes the majority of the load of the balls and role of door 8 is principally as a locking or cover means. If similar sized doors 8 and 10 are employed,

part of the weight of the balls is taken on door 8 and it becomes more difficult to operate opening arm 12. The long door 10 ensures clean opening and the load is rapidly deposited into the ball mill.

When the load has been emptied, arm 14 is moved to close door 10 and then arm 12 is moved to close door 8 and hence lock door 10 in the closed position. Thehandle 66 remains in the upper position, that is, the locking means 72 is out of engagement with arm 12. The empty drum 74, still inside the bucket 5, can be transported to the storage area, and lowered to the ground. The bail 2 is then lowered past ears 58 which now extend due to the action under gravity of the overbalance 62, as shown in FIG. 10. Once past ears 58, an upward pull on bail crossmember 3 may be applied and rotation about point commences and continues until the equipment rests on the l0-l5 sloping portions of members 20 and 22 as shown in FIG. 11. At this point the bail 2 is again lowered until stop 70 comes into operative locking engagement with bail lock member 68 as shown in FIG. 12. In order to facilitate this engagement, it is preferred that bail lock member 68 is a springloaded cam member. An upward pull on bail crossmember 3 can then be reapplied causing the equipment to rotate firstly about 78 and then about point 76 as shown FIG. 13 so that the bucket inverted position as shown in FIG. 1 is reattained. A further upward pull on the bail crossmember 3 lifts the bucket off the empty drum as shown in FIG. 14 and the equipment is then ready to turn, transport and unload the next drum.

Many modifications to the equipment described in detail herein will suggest themselves to those skilled in the art and therefore the disclosure must not be construed as limiting upon the present inventive concept. For example, the equipment may be adapted to unload particulate or lump materials contained in many designs of open-topped containers into furnaces and the like and the handle 66 could be operated automatically by means of hydraulic or pneumatic cylinders or by means of a solenoid valve. Many alternative forms of bail stops also fail within the scope of this invention without departing from the inventive concept as defined in the claims.

I claim:

1. A device for emptying particulate materials from an open-ended container, said device comprising: a bail having a crossmember and appendant arms; a bucket, having an opening in the base thereof, pivotably mounted adjacent the rim thereof for rotation about a horizontal axis between said bail arms between an upright position in which it discharges said particulate materials from said container inverted therein through said opening and an inverted position in which it is arranged to accommodate a sufficient proportion of said container whereby, on rotation from said inverted to said upright position, the container containing the particulate materials is inverted and picked up in said bucket and on reverse rotation the empty container may be released from said bucket; stop means connected to said bucket and adapted to allow free rotation of said bail about the pivotable mounting when the bail crossmember is lowered and prevent rotation of said bail about said mounting when said crossmember is raised whereby to cause, on raising said crossmember, rotation of said bucket between said positions; closure means movable between a closed position in which it closes said opening in said bucket and an open position; locking means adapted to releasably lock said bucket and said bail in said inverted position, said locking means being adapted on releasing said bail, to releasably lock said closure means in said closed position and to allow said closure member to be moved to said open position when said bucket is in the upright position and in a predetermined location for discharge of particulate material through said opening.

2. A device as claimed in claim 1 wherein said bucket is mounted within a frame of rigid members.

3. A device as claimed in claim 2 wherein some of said members are angulated with respect to said bucket, whereby to facilitate rotation of said bucket from said inverted to said upright positions.

4. A device as claimed in claim 1 wherein said stop means comprises a latch means, provided with an over balance, pivotably mounted to said bucket.

5. A device as claimed in claim 1 wherein said closure means comprises a pair of overlapping door members.

6. A device as claimed in claim 1 wherein said closure means comprises a door member and a cover member which overlaps said door member and, in conjunction with said locking means, as adapted to releasably lock said door member in said closed position.

7, A device as claimed in claim 1, wherein said locking means comprises a rod slidably mounted on said bucket; a spring cam means rigidly mounted on said rod adapted to releasably engage with said bail in said inverted position; means for moving said rod whereby said cam means may be moved into and out of engagement with said bail; and means to releasably lock said closure means in said closed position when said cam means is out of engagement with said bail.

8. A device as claimed in claim 7 wherein said rod protrudes beyond said bucket when said cam is out of engagement with said bail.

9. A device as claimed in claim 8 wherein the protruding portion of said rod is adapted, when said bucket is in said upright position, to contact a surface whereby said rod moves to a position wherein said lock means for said closure means disengages from said closure mean.

10. A device as claimed in claim 7 wherein said means for moving said rod comprises a handle for manual operation.

11. A device for emptying particulate materials from an open-ended container, said device comprising: a bail having a crossmember and a pair of appendant arms at right angles thereto; a bucket, mounted in a frame of rigid members, having an opening is the base thereof; said frame being mounted, adjacent the rim of said bucket, for rotation about a horizontal axis between said bail arms between an upright position in which it discharges said particulate materials from said container inverted therein through said opening and an inverted position in which it is arranged to accommodate a sufficient proportion of said container whereby, on rotation from said inverted to said upright position, the container containing the particulate materials is inverted and picked up in said bucket and on reverse rotation the empty container may be released from said bucket; latch means provided with an overbalance pivotally mounted to at least one frame member adapted to allow free rotation of said bail about said mounting when said crossmember is raised whereby to cause, on raising said crossmember, rotation of said bucket between said positions; a door member movable between a closed position in which it closes said opening in said bucket and an open position and a cover member which overlaps said door member; a spring cam means adapted to releasably lock said bucket and said bail in said inverted position, rigidly mounted on a rod slidably mounted on said frame; means for moving said rod whereby said cam means may be moved into and out of engagement with said bail, means to releasably lock said covennember in said closed position when said cam means is out of engagement with said bail; and means to allow said cover means and said door member to be moved to said open position when said bucket is in the upright position and in a predetermined location for discharge of said particulate material through said opening. 

1. A device for emptying particulate materials from an openended container, said device comprising: a bail having a crossmember and appendant arms; a bucket, having an opening in the base thereof, pivotably mounted adjacent the rim thereof for rotation about a horizontal axis between said bail arms between an upright position in which it discharges said particulate materials from said container inverted therein through said opening and an inverted position in which it is arranged to accommodate a sufficient proportion of said container whereby, on rotation from said inverted to said upright position, the container containing the particulate materials is inverted and picked up in said bucket and on reverse rotation the empty container may be released from said bucket; stop means connected to said bucket and adapted to allow free rotation of said bail about the pivotable mounting when the bail crossmember is lowered and prevent rotation of said bail about said mounting when said crossmember is raised whereby to cause, on raising said crossmember, rotation of said bucket between said positions; closure means movable between a closed position in which it closes said opening in said bucket and an open position; locking means adapted to releasably lock said bucket and said bail in said inverted position, said locking means being adapted on releasing said bail, to releasably lock said closure means in said closed position and to allow said closure member to be moved to said open position when said bucket is in the upright position and in a predetermined location for discharge of said particulate material through said opening.
 2. A device as claimed in claim 1 wherein said bucket is mounted within a frame of rigid members.
 3. A device as claimed in claim 2 wherein some of said members are angulated with respect to said bucket, whereby to facilitate rotation of said bucket from said inverted to said upright positions.
 4. A device as claimed in claim 1 wherein said stop means comprises a latch means, provided with an over balance, pivotably mounted to said bucket.
 5. A device as claimed in claim 1 wherein said closure means comprises a pair of overlapping door members.
 6. A device as claimed in claim 1 wherein said closure means comprises a door member and a cover member which overlaps said door member and, in conjunction with said locking means, is adapted to releasably lock said door member in said closed position.
 7. A device as claimed in claim 1, wherein said locking means comprises a rod slidably mounted on said bucket; a spring cam means rigidly mounted on said rod adapted to releasably engage with said bail in said inverted position; means for moving said rod whereby said cam means may be moved into and out of engagement with said bail; and means to releasably lock said closure means in said closed position when said cam means is out of engagement with said bail.
 8. A device as claimed in claim 7 wherein said rod protrudes beyond said bucket when said cam is out of engagement with said bail.
 9. A device as claimed in claim 8 wherein the protruding portion of said rod is adapted, when said bucket is in said upright position, to contact a surface whereby said rod moves to a position wherein said lock means for said closure means disengages from said closure means.
 10. A device as claimed in claim 7 wherein said means for moving said rod comprises a handle for manual operation.
 11. A device for emptying particulate materials from an open-ended container, said device comprising: a bail having a crossmember and a pair of appendant arms at right angles thereto; a bucket, mounted in A frame of rigid members, having an opening is the base thereof; said frame being mounted, adjacent the rim of said bucket, for rotation about a horizontal axis between said bail arms between an upright position in which it discharges said particulate materials from said container inverted therein through said opening and an inverted position in which it is arranged to accommodate a sufficient proportion of said container whereby, on rotation from said inverted to said upright position, the container containing the particulate materials is inverted and picked up in said bucket and on reverse rotation the empty container may be released from said bucket; latch means provided with an overbalance pivotally mounted to at least one frame member adapted to allow free rotation of said bail about said mounting when said crossmember is raised whereby to cause, on raising said crossmember, rotation of said bucket between said positions; a door member movable between a closed position in which it closes said opening in said bucket and an open position and a cover member which overlaps said door member; a spring cam means adapted to releasably lock said bucket and said bail in said inverted position, rigidly mounted on a rod slidably mounted on said frame; means for moving said rod whereby said cam means may be moved into and out of engagement with said bail, means to releasably lock said covermember in said closed position when said cam means is out of engagement with said bail; and means to allow said cover means and said door member to be moved to said open position when said bucket is in the upright position and in a predetermined location for discharge of said particulate material through said opening. 